Password handling needs improvement

[Atreidae]

As part of porting code from BounShell a lot of the SecureString handling relies on my old code for storing and retrieving secure variables.

This includes plenty of calls forcing SecureString to store stuff as plaintext, this needs to be updated and tested. and a new method of storing secure creds for the connection cmdlets for automated moves

[Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSAvoidUsingConvertToSecureStringWithPlainText', '', Scope='Function')] #Todo https://github.com/Atreidae/UcmPSTools/issues/24